Tobacco manipulating machines



April 30, 1968 F. A. M. LABBE TOBACCO MANIPULATING MACHINES 5 Sheets-Sheet 1 Filed July 5, 1966 Maw C044 hm+w a I P 1968 F. A. M. LABBE 3,380,782

TOBACCO MANIPULATING MACHINES Filed July 5, 1966 5 Sheets-Sheet 2 April 1968 F. A. M. LABBE 3,380,782

TOBACCO MANIPULATING MACHINES Filed July 5, 1966 5 Sheets-Sheet 5 April 30, 1968 Filed July 5, 1966 F. M. LABBE TOBACCO MANIPULATING MACHINES 5 Sheets-Sheet 4 April 1968 F. A. M. LABBE 3,380,782

TOBACCO MANIPULATING MACHINES Filed July 5, 19% 5 Sheets-Sheet 5 United States Patent 3,380,782 TOBACCO MANIPULATING MACHINES Francis Auguste Maurice Labb, Neuilly-sur-Seine,

France, assignor to Moiins Machine Company Limited, London, England, a corporation of Great Britain Filed July 5, 1966, Ser. No. 562,756 Claims priority, application Great Britain, July 9, 1965, 29,273/65 14 Claims. (Cl. 302-51) ABSTRACT OF THE DISCLOSURE In a cigarette-making machine in which tobacco is pneumatically conveyed through a confined passage to a conveyor, air is guided towards the passage inlet from two sources in converging paths and entrains to acco where the two paths merge. The passage inlet is bifurcated by either a stationary plate or a belt conveyor along which tobacco is directed. Curved vanes may be provided to assist in guiding the air. One of the air streams is admitted through an adjustable opening into the enclosed zone through which tobacco is fed from the hopper towards the passage inlet.

This invention concerns improvements in tobacco manipulating machines of the kind where cut tobacco, or tobacco in the form of pieces of lamina, is fed from a supply and subsequently becomes airborne in an airflow which conveys it, for example, to a device where it is formed into a tobacco filler. The most notable of such machines are continuous-rod cigarette-making machines.

In a well-known form of such cigarette machine the tobacco is carried by the airflow through a passage towards a porous or perforated conveyor on which the airborne tobacco builds up to form a filler and, usually, the airflow is caused by suction exerted through the conveyor which is commonly an air-pervi us band. The invention will be explained in more detail later as applied to such a machine but this is merely by way of explanation and not of limitation.

In such a cigarette machine tobacco may be removed from a hopper or other source of supply by a carded roller from which the tobacco is picked and thrown into an airstream in which it is carried airborne to said porous conveyor. Such tobacco as does not become ainborne comprises, in the main, fragments unsuitable for incorporation into .a cigarette filler and after these have been subjected to passage through further ai-rstrearns to remove as far as possible any light and usable fragments which are still among the unsuitable fragments, the rest is discarded. \Vhere this winnowin-g process is not necessary the conveyance of the tobacco to the filler forming device, for example, the porous conveyor, may be effected in a different way which forms the subject of this invention.

According to the invention there is provided a method of conveying tobacco, comprising the steps of causing air to flow in two converging paths merging into a single path, and directing tobacco to the region where the two converging paths merge into the said single path so that the tobacco is entrained by air at that region and is conveyed by the air along said single path.

The tobacco may be directed along a path extending between the said two converging paths to the region where the latter merge into a single path and its path may be substantially equi angularly disposed to the said two c nverging paths.

Further according to the in'vention there is provided in a tobacco-manipulating machine such as a cigarette-making machine, a method of conveying tobacco from a 3,386,782 Patented Apr. 39, 1968 source of supply to a place where it is formed into a filler, said method comprising the steps of directing tobacco to the region of confluence of two airstreams so that it becomes airborne between the two airstreams and is substantially confined to the core, as herein defined, of the airflow resulting from the confluence of the two airstreams.

Still further according to the invention there is provided tobacco feeding apparatus, wherein tobacco is conveyed pneumatically, comprising means to cause air to flow in two converging paths which merge into a single path, and means to direct tobacco (e.g. along a path extending between said converging paths) to the region where the two converging paths merge, whereby the tobacco is entrained by air at that region and is conveyed by air along said single path.

Means may be included for varying the flow characteristics of the air in one of the two converging paths relatively to the characteristics of the air in the other path.

The apparatus may include a confined passage along which air flows in said single path, and having an inlet to admit air and tobacco, means to draw air into and through the passage, guide means to guide air in the said two converging paths which merge at said inlet, and means to direct tobacco to said inlet to be entrained by air moving into and through the passage. The inlet to said passage may be bifurcated by a member along one surface of which the tobacco is directed. Said member may be a stationary plate or part of a belt conveyor. Vanes may be interposed between said member and one wall of said passage, the vanes being adapted to effect a change in direction to the air flowing therethrough.

Further according to the invention there is provided a tobacco manipulating machine comp-rising a tobacco hopper and a carded roller rotatable in said hopper to remove to bacco therefrom, a picker roller arranged to pick tobacco from the carding of said roller and a plate to receive the picked tobacco with a ribber roller arranged to project the tobacco along said plate, a passage through which the tobacco is conveyed by an airflow, with a porous conveyor at the end of the passage on which the tobacco is formed into a tobacco filler, the entry to said passage being closed-in except for two inlets through which air can enter as two distinct streams which merge at the entry of the passage to form the airflow, the said plate being positioned to lead the projected tobacco between the streams to the point where they merge, said streams and said airflow being caused by suction exerted through the porous conveyor.

Various embodiments of apparatus according to the invention will be described by way of example with reference to the accompanying drawings in which:

FIGURE 1 is an elevation, partly in section, of the filler forming portion of a continuous-rod cigarette-making machine of the kind outlined above,

FIGURE 2 is a transverse section through a machine of this kind showing one way of applying the invention thereto,

FIGURE 3 shows some modifications to the structure shown in FIGURE 2,

FIGURE 4 shows an arrangement similar to FIGURE 3 with some additional features and a control device for one airstream,

FIGURE 5 is a transverse section through a machine of the kind outlined above but shows a way of applying the invention which differs from the showing of FIGURE 2,

FIGURE 6 shows an arrangement for feeding tobacco to two airstreams, somewhat similar to that of FIGURE 4, but the tobacco is conveyed downwards by the resulting airflow to form a filler on a porous conveyor at the bottom of the figure,

FIGURE 7 shows another arrangement for feeding tobacco. downwards to a porous conveyor,

FIGURE 8 is a section of part of the apparatus of FIGURE 2 drawn to an enlarged scale,

FIGURE 9 is a diagram of tobacco and air flows; and

FIGURE 10 is a diagram giving air velocities in one part of the apparatus.

Referring first to FIGURES 1 and 2, tobacco is fed from a hopper by a carded roller 1, surplus tobacco being removed from the top of the roller 1 by a refuser roller 2. In general tobacco is picked from the roller 1 by various devices to be described hereinafter and is delivered to the base of a narrow confined passage 3 up which it is carried by an airflow caused by suction through a porous conveyor 4, the tobacco finally adhering to the underside of this conveyor to form a filler. The filler moves along with the conveyor in the direction of the arrow (FIGURE 1) and is trimmed by a trimmer 5 to bring the til er to a desired volume.

The carded roller 1 is located in the base of a hopper 6 and, as the roller 1 rotates in the direction of the arrow (FIGURE 2), it picks up tobacco and carries it beneath the refuser roller 2 which removes surplus tobacco so that the teeth of the carding on roller 1 become evenly filled with tobacco. The tobacco passes beneath a toothed comb 7 which controls it while a picker roller 8 removes the tobacco from the carding on the roller 1, the picked tobacco being thereby directed along the curved surface of a concave plate 9 and projected by a ribbed roller 19 towards the entry of the passage 3. At the top of this passage 3 is the porous conveyor 4 and above it is a chamber 1%) which is connected to a fan, not shown, which draws air from the chamber and through the conveyor thus causing an airflow up the pass-age 3. The effect is augmented by a further suction chamber 11 connected to a further fan not shown, which draws air through a grille 12. Underneath the roller 17 is a shroud 13 which catches dust and shorts falling from the roller, these being delivered through a converging passage 14 to a suction pipe or like conveyor 15 which carries the fragments away, an airlock being provided by a rotary valve 16. All the details so far recited are known.

Above the picker roller 8 and the ribbed roller 19 is a cover plate 17 which is perforated and provided with a perforated slidable shutter 18 whereby the effective area of the perforations for the passage of air may be adjusted. The suction in the chamber causes an airflow up the passage 3 which is due partly to air sucked through the perforations as indicated by the arrows, and this air constitutes one air flow B. It will be noticed that the edge of the concave plate 9 is thinned and the thin part just enters the bottom of the passage 3 but is spaced from a wall thereof so that air is also sucked through this space to provide a second airflow A. The point where two arrows, one for each airflow, join may be regarded as the region of confluence of the two airflows. Because of the shape of the concave plate 9 and the disposition of the ribbed roller 19, it will be seen that the tobacco is thrown right between the two airflows at the region of confluence and with the path 'of the tobacco at substantially equal angles to the two airflows.

FIGURE 3 shows a generally similar arrangement, the only difference being that the concave plate, marked 9A, is shorter and the entry to the passage 3 is extended to 3A to shift the region of confluence accordingly. The direction in which the tobacco is thrown is therefore different. The substantially horizontal throw of the tobacco in this particular instance requires a higher velocity of the airflow A in order to keep the tobacco particles in the core of the airflow.

The arrangement in FIGURE 4 is generally similar to that of FIGURE 3 but three curved vanes 20 are arranged in the path of the first airflow B just near the point of confluence. The purpose of these vanes will be given later in the general description of the functions of all the different structures shown on the drawings.

In FIGURE 5 the tobacco picked from the carded roller 1 falls on to a conveyor belt 21 which carries it to the point of confluence of the two airflows. In this case roller 21a causes the tobacco carried by the conveyor belt 21 to be directed into the region where the two airflows B and A merge into a single flow up the passage 3. Vancs 20a are shown and perform a similar function to the vanes 20 of FIGURE 4, but this time on airflow B instead of airflow A. The passage 3 is shown in full lines and also in broken lines as the passage 3 may be directed either upwards or downwards.

Referring now to FIGURE 6 it will be seen that the passage 3 has been inverted as compared with FIGURE 2 and the porous conveyor 4 is now at the bottom of the view. As all the parts associated with the passage are identical with those of FIGURE 2 any further description is not necessary except that as the concave plate is of slightly different shape it is marked 9B.

FIGURE 7 also shows an inverted passage 3 and the picking and throwing of the tobacco is conducted entirely by the picker roller 8, the plate over which the tobacco is picked having a flat face and it is therefore marked 9C. The perforated cover plate and its perforated shutter are of arcuate form and are marked 17A and 18A respectively.

It will be understood that the control of the airflows A and B so that they move in the correct directions and meet at the desired place is of great importance and thus the entry of air to the system is controlled by sundry guides as will now be described.

In FIGURES 2 and 3 the picking and ribbed rollers, 8 and 19 respectively, are completely enclosed as the plate 17 has a seal, such as a soft pad 22, which closes the gap between the plate 17 and a plate 23 which is part of the normal structure of the machine. Thus air for airflow A can only enter through the space between the end of the concave plate and the end of the passage 3 while air for airflow B can only enter through the perforations in 17 and 18. It will also be seen from this view that the tobacco is thrown by roller 19 along a path which is substantially equi-angularly disposed to the paths of the airflows A and B at the region of confluence and is in line with the path of the airflow formed by the merging together of the two airflows. This relative disposition of the path of the thrown tobacco and the two airflows and the resulting airflow is however only incidental to the structure shown. In fact the directions of the two airflows A and B are not so very important provided they do not disturb the tobacco. For instance if airflow B moves with a very low velocity v no means of directing it, such as is provided by the vanes 20 shown in FIGURE 4, is necessary.

FIGURE 8 is a diagram showing the airflows and tobacco path more clearly in the case where airflow B has this low velocity, The tobacco path is shown by a thick inclined arrow T and the airflow by a thin inclined arrow C and it will be seen that they are in a straight line.

In FIGURE 4, air for airflow B is similarly controlled. The air for airflow A comes up a sloping passage 24. This does not affect the airflow A itself but the purpose of passage 24 is to use this airflow for lifting any shorts falling between the concave plate 9A and the drum 1.

The general theory of the relative dispositions of the paths of the tobacco and airflows will now be explained with reference to the diagram, FIGURE 9. The middle arrow T represents the path of the thrown tobacco and the side arrows the paths of the two airflows but their velocities are also concerned so that the arrows are marked V and V If M is the mass flow of airflow A and M is the mass flow of airflow B, then the angles 0 and 6;, must be such that M X V XSIH Q ZM X VBXSIH 0 Therefore angles 0,, and need only be equal if the momenta M X V and M X V are equal.

In FIGURE 5 the space surrounding the picker roller is closed in by the conveyor 21, with a sealing pad at 25 and an upper shield 26 which has an air inlet 27 with a perforated control slide 28 adjustable over perforations in the shield 26. This arrangement controls airflow B while air for airflow A comes in through ducting 29, one wall of which extends ot form a wall of the passage 3, while the other wall fits closely against the conveyor belt 21.

The arrangements in FIGURES 6 and 7 are the same as for FIGURE 4 so no further description is necessary.

FIGURE 10 will help to explain how the tobacco is entrained in th single airflow along the passage 3, and the intended mean mg of the term core as used in the introdnctlOn to the specification and in the appended claims will be explained with reference to this figure. The airflow along the passage 3 has a velocity V, and although the walls are smooth there is necessarily a change in the velocity distribution across the distance between the wall". of the passage. Near the walls there is a large velocity gradient, dV/dx, while at the middle part of the airflow the velocity is substantially uniform. This part, marked C in the diagram is the core. The best result is obtained when the tobacco particles are spread over, but confined to, the width of the core C. The smoother the walls, the wider the core. If the walls should be slightly rough the velocity distribution curve tends to take the form shown in broken lines with a higher peak giving a narrower core. The boundary layers of the airflows are indicated by cross hatching and it is highly desirable that these should not contain any tobacco.

The disposal of shorts depends on the structure concerned and the desires of the user. So far as shorts on the concave plate 9 are concerned these are disposed of in the same way as the tobacco.

In FIGURE 2, for example, shorts carried along the pipe may be delivered on top of the mass of tobacco in the hopper or fed to the partly-formed filler in the manner described in copending application Ser. No. 388,- 212 filed Aug. 7, 1964, in the names of Desmond W. Molins and Francis A. M. Labb.

In FIGURE 4, shorts falling away from roller 1 at the picking position take the direction indicated by arrows S and can enter the passage 24 through a gap 30 so that they can joint tobacco in the passage 3. The same arrangement is shown in FIGURES 6 and 7 while FIGURES 3 and 5 can have the same suction pipe device as shown at the bottom of FIGURE 2, and for the general collection of shorts from the lower part of the roller 1 all the other constructions can have similar suction pipe arrangements.

It was stated earlier when referring to FIGURES 2 and 3 that the tobacco is directed along a path which is substantially equi-angulariy disposed to the airflows A and B at the region of confluence but it will be seen in FIG- URES 4 and 5 that the tobacco leaving the end of the concave plate 9A, or the conveyor belt 21 respectively, is virtually crossing the general direction of the airflow B in the first case and the general direction of the airflow A in the second case. The curved vanes are therefore provided to direct the respective airflows to produce the desired disposition of the airflows A and B with respect to the tobacco and thus to avoid any interference by the airflows with the moving tobacco.

The relative velocities of the airflows A and B are determined by the perforated control slides, or other suitable control means, in order to keep the tobacco particles in the core of the airflow.

In FIGURE 3, for instance, flow A is faster than flow B while in FIGURE 6, B is faster than A. In general the airflow which is to form the outer portion of the airflow at the following bend is made to have the higher velocity.

Air for the two flows may come either from atmosphere or from fan outlets as may be convenient.

In machines of the kind where the filler is formed on a porous conveyor it is necessary that for correct filler formation the tobacco should be projected onto the conveyor in separated particles and to achieve this, tobacco passing through the passage 3 should be strongly accelerated. In the present case since the tobacco is at the core of the airflow formed by the two merging airflows very satisfactory separation is secured as the acceleration required is exerted over a stream of tobacco particles which is comparatively narrow in relation to the width of the passage 3, as any tendency for the tobacco particles to migrate towards the walls of the passage where they may be slowed down is reduced to a minimum.

Referring again to FIGURE 1, the passage 3 is shown sloping to the left. In this case the airborne tobacco has a component of movement in the direction of movement of the conveyor 4. This is not necessary in some designs of the machine and a vertical passage has been used. Where a sloping passage is used deflecting means in the form of a honeycomb mesh 31 is provided in one wall of the passage entry to give the fast moving air the necessary component of movement.

The mesh 31 is provided by a block having numerous small holes made in it and these are inclined from the vertical in two directions so that air passing through will be directed both towards the left-hand wall of the passage 3 in FIGURE 2 and also towards the left in FIG- URE 1. The block is described in some detail in the copending application Ser. No. 516,536 filed Dec. 27, 1965, in the names of Desmond W. Molins and David T. N. Williamson to which reference may be made. In the present case air for the airflow A can be passed through such a block by suitable rearrangement of the parts.

The necessary component of movement can be obtained only with very fast moving air through the deflecting means, that is, the honeycomb. Therefore the angle 0 of this air must be very small since from the formula set out above (M XV sin 0;, SlIl 0 X (MAXVA) VA VB.

The very fast moving air must have a longitudinal component parallel to the tobacco fleece and its direction must be controlled by the honeycomb in both forward and lengthwise directions,

An airflow having a speed of 10 metres/sec. is satisfactory but higher velocities may be employed.

Hitherto the description has related to a machine in which the filler is formed on a porous travelling conveyor band but this is not an essential arrangement as other porous conveyor devices are known to which the invention might be applied with suitable structural rearrangements. Further a porous conveyor is not an essential as in US. Patent No. 3,019,793 in the name of Francis A. M. Labb there is described an arrangement where a passage like 3 is inverted, as in FIGURES 6 and 7, but at the lower end of the passage the Walls are perforated so that the air can escape while the travelling tobacco is delivered to an imperforate conveyor on which it forms a filler.

I claim:

1. A method of conveying tobacco, comprising the steps of causing air to flow in two converging paths merging into a single path, and directing tobacco to the region where the two converging paths merge into said single path so that the tobacco is entrained by air at that region and is conveyed by the air along the core of said single path, said core being the central portion of the airflow in said single path where the velocity is substantially uniform.

2. A method as claimed in claim 1, wherein the tobacco is directed along a path extending between said two converging paths to the region where the latter merge into a single path.

3. A method as claimed in claim 2, wherein the path of the tobacco is substantially equi-angularly disposed to the said two converging paths.

4. A method as claimed in claim 2 wherein the relative dispositions of said two converging paths of airflow and said path of tobacco are in accordance with the formula:

M X V Xsin Q M XV XSlIl wherein A and B represent the two airflow paths respectively, M A and M are the mass flow of air in each of the two airflow paths respectively, V and V are the velocities of air in each of the two airflow paths respectively and 0 and 0 are the angular relationships between the tobacco path and each of the airflow paths respectively.

5. Tobacco-feeding apparatus, wherein tobacco is conveyed pneumatically, comprising means to cause air to flow in two converging paths which merge into a single path, and means to direct tobacco to the region where the two converging paths merge, whereby the tobacco is entrained by air at that region and is conveyed by air along the core of said single path said core being the central portion of the airflow in said single path where the velocity is substantially uniform.

6. Tobacco feeding apparatus as claimed in claim 5, comprising means for varying the flow characteristics of the air in one of the two converging paths relatively to the characteristics of the air in the other path.

7. Tobacco-feeding apparatus as claimed in claim 5, including a confined passage along which air flows in said single path, and having an inlet to admit air and tobacco, means to draw air into and through the passage, guide means to guide air in said two converging paths which merge at said inlet, and means to direct tobacco to said inlet to be entrained by air moving into and through the passage.

8. Tobacco feeding apparatus as claimed in claim 7, wherein the inlet to said passage is bifurcated by a member along one surface of which the tobacco is directed.

9. Tobacco feeding apparatus as claimed in claim 8 wherein said member is a stationary plate.

10. Tobacco feeding apparatus as claimed in claim 8 wherein said member is part of a belt conveyor.

11. Tobacco feeding apparatus as claimed in claim 3, comprising vanes interposed between said member and one wall of said passage, the vanes being adapted to effect a change in direction to the air flowing therethrough.

12. Tobacco feeding apparatus as claimed in claim 5 wherein said means to direct tobacco comprises a third path extending between said converging paths.

13. Tobacco feeding apparatus as claimed in claim 12 wherein said means to cause air to flow in said two converging paths and said means to direct tobacco along a third path are capable of directing said paths such that the relative positions of the two converging paths of airflow and said path of tobacco are in accordance with the formula:

AIAX V XSiII 0 ZM XV XSiH 03 wherein A and B represent the two airflow paths respectively, M and M are the mass flow of air in each of the two airflow paths respectively, V and V are the velocities of air in each of the two airflow paths respec tively and 8 and 0 are the angular relationships between the tobacco path and each of the airflow paths respectively.

14. A tobacco manipulating machine comprising a tobacco hopper and a carded roller rotatable in said hopper to remove tobacco therefrom, a picker roller arranged to pick tobacco from the carding of said roller and a plate to receive the picked tobacco with a ribbed roller arranged to project the tobacco along said plate, a passage through which the tobacco is conveyed by an airflow, with a porous conveyor at the end of the passage on which the tobacco is formed into a tobacco filler, the entry to said passage comprising two inlets through which air can enter as two distinct streams which merge at the entry of the passage to form the airflow, the said plate being positioned to lead the projected tobacco between the streams to the point where they merge, said streams and said airflow being caused by suction exerted through the porous conveyor.

References Cited UNITED STATES PATENTS 740,097 9/1903 Davis 302-36 3,030,966 4/1962 Lanore 13184 3,138,163 6/1964 Ffo'ulkes 13184 3,189,034 6/1965 Molins 13l84 ANDRES H. NIELSEN, Primary Examiner. 

